SHUTTLE_STEEL_STRUCTURE

SHUTTLE制作工艺
Fabrication Procedure for Shuttle Steel structure
一、SHUTTLE STEEL STRUCTURE结构概述
Brief Introduction to Shuttle Steel Structure
SHUTTLE STEEL STRUCTURE为弧形框架结构，现以其中第一段为例简述其建造工艺。

SHUTTLE结构形式如下图
Shuttle Steel Structure is arc-shaped frame structure and this procedure is based on one of the sections as an example. Please see the shuttle structure picture as below:
二、关键尺寸及制作难点Key Topics
1.工字钢变形控制H Beam welding distortion control
2.整体框架尺寸Shuttle frame dimension control
3.Rack 尺寸控制（同轴度、弧度）Rack hole dimension control
( axiality、radian)
三、制作方案Fabrication Plan
根据shuttle的结构特点和机加工的技术要求，shuttle采用倒装的方式建造，shuttle装焊报验合格后进行镗孔。

其中工字钢采用侧装的方式进行建造。

The Shuttle will be fabricated in inversion-fitting method and the line boring will be carried out after welding inspection according to its structure characteristic and technical requirement of machining. The “工” steel structure will apply side-fitting method.
四、制作流程Fabrication Process
4.1框架制作Frame Fabrication
流程4.1.1：工字钢拼接H beam fabrication
Step 4.1.1: Top plate & web plate of H Beam frame splicing.
1）腹板拼板Web plate splicing
☆腹板板厚较薄，在拼板制作时，在四周用小的卡码卡住然后再进行装配、焊接。

☆The web plates must be fixed on the jig by clamps while splicing because it is only 6mm which is very easy to get distorted.
☆腹板拼版过程中采用槽钢进行加强以减少变形。

☆U-steel should be used as strengthen to avoid distortion on flatness.
☆拼板在胎架上进行（板厚差），拼板完成之后进行平面度矫正。

☆Splicing must be done on the jig. Flatness must be checked and rectifying after splicing.
2）安装腹板纵向加劲肋板
2）Fitting & wielding of strengthening plate.
☆加强筋安装前划线及打磨处理
☆Marking fitting line of strengthen plate. The make line must be lay out in true measurement on computer, 30mm width of fitting line must be grinded before fit up.
☆焊接时严格按照先立后平、先中间后四周的顺序焊接，长度大于2米的长焊缝采用分中退焊的方法焊接较少焊接变形（焊接平角焊时要求施工人员先焊结构正面，待结构正面的焊缝自然冷却后再焊结构背面）。

☆Vertical welds must be welded first then the downward welds.
☆The weld which is longer than 2m must be welded from the center to the end.
☆Flatness must be checked and rectified before inside strengthen fitting up.
3) 组拼工字梁
3) H-beam fitting & welding
☆Critical dimension 2600±1.5: To keep this dimension, welding shrinkage must be considered. So fit-up dimension measurement must be carried before welding. The fit-up dimension is 2600+4mm(4mm for welding shrinkage)
☆Welding sequence
为防止工字梁扭曲变形，必须避免图5
中B 所示焊接方向，因为相邻焊缝焊接方向相反，角变形沿着焊缝长度逐渐增大，会使构件扭转。

The welding method in picture B is forbidden to avoid “工” steel deflection because opposite welding direction of two close welding seams will result in the angle distortion increase along with the welding seam length.
4) 安装工字钢加劲板
4) Installation of strengthening plate
流程4.1.2：框架大合拢Assembly
1）An Inverse-assembly method jig is required and the top of jig must be arc-shaped as the same as the shuttle. H-Beam should be fixed by clamps.
☆上胎后工字钢加斜撑固定工字钢，保证两工字钢间距
☆H-beam must be supported by bracing. Dimension from CL
to CL (5400) must be double checked.
2) 安装连接工字钢
2) Fitting & welding of braces
☆Temporary bracing must be used to keep the shape and dimension.
3) 安装连接板下牛腿
3) Fitting up & welding of corbel
☆Corbel will be fitted without connecting plate. The connecting plate must be welded when fit the rack.
4.2 针轴件制作Rack fabrication
1) 顶底板拼板（连接板处加厚，16mm改成20mm，用于机加工）
1) Splicing of top plate. The item which is connect to the shuttle structure must be machined after welding. PL20mm must be used for this item to make sure enough machining green.
2) The connecting plate will be machined to flat. The arc of this plate is only 0.4mm which can be ignored.
3) Temporary strengthen rib must be used to keep the dimension and avoid distortion.
焊接时加装隔板用于保型，先用分中退焊法焊接外侧两条角焊后再焊接里面焊缝，由于所有焊缝偏向中性轴一侧，焊接时两头刚性固定，焊后退火拆除，防止整个针轴焊接后产生较大挠曲变形。

4)Rectifying after welding must be carried to keep the
straightness of rack.
4.3 组装Assembly
1) Rack assembly
1) Connecting plates must be match drilled. And, these two plates must be bottled together while welding.
2) Machining marking line must be marked when the rack is tighten bottled to the shuttle structure.
3) Dismount rack from the shuttle structure and line boring the holes by CNC machine.
4) Re-assembly
1)Dummy shaft must be used before install the rack. At least 2
dummy shaft must be used .
2)Connecting plate must be used to keep the dimension between
two racks.。